Limited cycle life remains a major obstacle to the practical application of high-capacity alloy negative electrodes in rechargeable batteries aimed at boosting energy density. The key challenges lie in the inherent uncontrollable volume changes and unstable electrode-electrolyte interphases. Here, we demonstrate a long-life self-construal tin (Sn) negative electrode for sodium (Na)-ion batteries enabled by in situ-formed embedded C-N anchors that integrate mechanical and chemical restrictions. This effect reshapes the alloying reactions with pronounced phase transformation hysteresis and triggers an electrochemically driven self-reconstructed structure for alloying reactions, therefore resolving the uncontrollable volume expansion and associated detrimental effects. C-N anchors also promote the formation of unique viscoelastic electrode-electrolyte interphases that comfortably accommodate large volume fluctuations for thousands of cycles. The designed Sn-based negative electrode exhibits long cycle life over 7000 cycles with a low-capacity decay rate of ~0.0036% at 2 C. Stable cycling of the Sn-based negative electrode is further confirmed in a prototype Na-ion pouch cell. This work offers an efficient design of employing the inherent volume expansion of alloy to electrochemically induce a self-constructed structure that comfortably accommodates volume changes, thereby ensuring long cycle life.

Optimizing electrolyte saturation in partially wetting electrodes of Li-O2 batteries: A coupled electrochemical and mass transport modeling approach

Synergistic H+/Zn2+ insertion mechanism in N/Co co-doped HxV2O5 film electrodes for aqueous zinc-ion batteries

Understanding dual-ion storage benefits and challenges of all carbon-fiber-plate candidate electrodes in sodium-ion structural batteries

The cation effect on halogen intercalation into graphite electrode in aqueous zinc dual-ion batteries

Transition metal MN4 macrocycle-derived bifunctional ORR/OER electrocatalysts for air electrodes in rechargeable zinc-air batteries

Study of M-N-C@FeNPs (M: Fe, Co, Ni) bifunctional electrocatalysts as positive electrodes for rechargeable Zn-air batteries

Graphite felt anchored with fused nanowires from bismuth metal-organic framework as negative electrode for all-vanadium redox flow batteries

Investigation of drying characteristics and evaluation strategy for wet coating in the manufacturing process of battery electrode

BS-Mamba: A battery-specific Mamba network for robust battery electrode CT image segmentation

Rational design strategies for MXene-based architectures in aqueous zinc-ion battery electrodes

Laser ablation of high-loading Li-ion battery electrodes improves accessible capacity and cycle life for Behind-the-Meter Storage

Under fast charging and high-rate discharge conditions, lithium-ion battery electrodes experience significant stress variations, leading to capacity decay, reduced cycle life, and potential safety risks. Accurate and efficient prediction of stress distribution in electrodes is essential for optimizing battery performance and safety. We propose a simplified pseudo-2D (SP2D) model for rapid, precise prediction of voltage, lithium-ion concentration, and electrode stress. The SP2D model was developed and validated under typical operating conditions, including galvanostatic discharge, high-frequency multi-level pulses, dynamic urban dynamometer driving schedule profiles, and asymmetric charge–discharge cycles. Results show that the SP2D model achieves high computational efficiency, 3 to 9 times faster than the P2D model, while maintaining errors in lithium-ion concentration and stress within 5%. Validation across LG M50 (capacity-type) and Enertech (power-type) cells revealed systematic variations: capacity-type cells show increased errors in terminal voltage at high rates (over 1 C), with root mean square error (RMSE) reaching 0.0442 V at 2 C, while power-type cells exhibit lower voltages but higher accuracy (average RMSE 0.00352 V). These deviations are attributed to differences in electrolyte transport and electrode properties, leading to peak stress prediction errors near the electrode/separator interface up to 29.76%. This work provides an effective modeling tool for real-time state monitoring and management of lithium-ion batteries.

In this paper, the electrochemical performance of two nitrogen-based ionic liquids (ILs), 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide (BMPyr-TFSI) and 2,3-dimethylimidazolium bis(trifluoromethylsulfonyl)imide (BMMI-TFSI), with different concentrations of NaTFSI, as electrolytes for the Na0.67Ni0.33Mn0.67O2 (NNM) positive electrode for sodium-ion batteries (SIBs) were compared with the conventional 1.0 mol L-1 NaClO4 in carbonate electrolyte. Moreover, the influence of salt concentration on the physicochemical properties of both ILs was evaluated. Amidst the neat ILs, BMPyr-TFSI showed better transport properties than BMMI-TFSI, whereas, for NaTFSI-mixtures, adding salt was detrimental to the ILs' properties. The poorer transport properties of the ILs compared to those of the carbonate electrolyte negatively impact the NNM electrode performance. At C/10, the highest discharge capacity obtained in IL mixtures was 40 mA h g-1 for BMPyr-TFSI with 0.5 mol L-1 of NaTFSI, compared to 59 mA h g-1 for NNM in NaClO4 electrolyte. Lowering the current density improved the performance of NNM in both BMPyr and BMMI-based mixtures, achieving specific capacities and Coulombic efficiencies above 53 mA h g-1 and 96%, respectively, at C/50. This approach has proven effective in overcoming the kinetic limitations due to the poorer transport properties displayed by ILs, encouraging the implementation of these electrolytes in SIBs.

Lithium-ion batteries (LIBs) have become a vital part of the world's energy storage solutions over the past decades, mostly in the small electronics and electric vehicle markets. Lithium's high energy density and graphene's superior electronic properties make them a perfect combination for the most common LIBs used today. In recent years, other nanomaterials such as graphyne have emerged as highly promising candidates for innovative electrode designs. To explore this potential, the present study employs density functional theory (DFT) calculations to systematically investigate the structure and electronic properties of 56 unique graphyne compounds, evaluating their suitability as cathode materials for LIBs. A total of eight substituents were considered in this study, namely carbonyl, nitrile, nitro, carboxyl, trichloromethyl, trifluoromethyl, sulfeno, and dimethylamino groups. This study reveals that, among the functional groups analyzed, nitro and carbonyl groups consistently yielded the most significant enhancements in redox potential, achieving values as high as 5.0 V and 2.9 V, respectively. Other substituents did not impact the redox potential when compared to the pristine state with the exception of tetrasubstituted trifluoromethyl graphyne that reached a potential of 2.9 V. Moreover, the study demonstrates that the highest redox potentials in multi-substituted graphyne compounds were associated with locally distributed configurations, highlighting the benefits of controlled substitution within the graphyne framework.

Solid-state batteries promise higher energy density and safety, but simply replacing liquid electrolytes with solid ones does not guarantee improvement over lithium-ion batteries. Achieving higher energy density requires high active material (AM) content and high AM loading, which is hindered by solid-state electrolyte's (SSE's) low ionic conductivity, poor AM-SSE interfaces, sluggish Li+ transport, and processing challenges. In this review paper, the fundamental mechanisms of ion transport in SSEs and composite electrodes are comprehensively reviewed and discussed. It is found that reducing the internal ionic resistance and the diffusion impedance of AM are effective ways to boost the effective current density of the composite electrode and decrease the overpotential of SSBs to enhance the delivered energy. The mechanisms and advanced techniques for measuring both ionic and electronic conductivities, as well as directly observing the ionic conductivity and diffusion of the composite electrodes are summarized. Furthermore, the strategies for improving ion diffusion within the AM, and enhancing ion transfer across the high AM content composite electrode are discussed. In addition, the challenges associated with industrialization of composite electrodes and potential solutions are discussed. This review paper summarizes the key aspects of ion transport in the solid-state composite electrode, aiming to support the design of ultrahigh energy density SSBs.

The two common characterization techniques that can distinguish between the metastable 1T and stable 2H phase of molybdenum disulfide (MoS2) are Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Argon ion etching within XPS offers the possibility to explore sample composition as a function of depth. However, for 2H MoS2 samples this results in sample alteration via the creation of sulfur vacancies and leads to local areas of MoS2‑x and 1T/2H MoS2. XPS MoS2‑x generation (228.1 eV) and laboratory nanoscale 1T MoS2 synthesis (228.4 eV) are easily mistaken in XPS, as both signals exhibit downshifted Mo 3d binding energies relative to 2H MoS2 (229.3 eV). Thus, we applied a four split orbit peak XPS model that enables distinction between MoS2‑x alteration and successful 1T phase synthesis. In argon etching induced MoS2‑x the pristine S 2p peaks remain dominant (162.0 eV) and the S/Mo atomic ratio decreases from 2.5 to 1.1 after electrode ion bombardment. When nanoscale 1T MoS2 forms during lithiation in a lithium-ion battery, the dominant S 2p peaks are found at lower binding energies (161.5 eV) and the S/Mo atomic ratio is elevated (>2.0). Depth profiling of ex situ 1T/2H MoS2 electrodes showcases lithiation beyond the electrode surface, clearly distinguished from solely MoS2‑x alteration through the S 2p component percentage, which exceeds the 1T MoS2 limiting threshold (1T > 13% of S 2p) for ion bombarding of as-cast electrodes.

Aqueous Mg-ion batteries (AMIBs) have emerged as promising candidates for grid-level energy storage systems, thanks to their exceptional safety characteristics, cost-effectiveness, and abundant Mg resources. However, AMIBs confront great challenges, such as the shortage of high-performance electrodes and the sluggish Mg2+ diffusion in the electrodes. In this work, a Mg2+-regulated bilayered vanadium oxide (MgVOnH) positive electrode, holding a large interplanar spacing of ∼13.4 Å, was investigated in 0.8 m Mg(TFSI)2-85% poly(ethylene glycol) (PEG)-15% H2O and 0.8 m Mg(TFSI)2-65% PEG-20% dimethyl sulfoxide (DMSO)-15% H2O (20% DMSO-containing) electrolytes. MgVOnH delivers a first discharge capacity of 268 mAh g-1 at 50 mA g-1, obtaining 81% capacity retention after 100 cycles (against a second discharge capacity of 249 mAh g-1) in a DMSO-free electrolyte, whereas MgVOnH exhibits much better rate capability and high capacity at 500 and 1000 mA g-1 in the DMSO-containing electrolyte, respectively. Particularly, MgVOnH shows a first discharge capacity of 106 mAh g-1 at 1000 mA g-1, maintaining 80/65% of its capacity after 920/2000 cycles. Furthermore, the electrochemical reaction mechanism and reversibility of MgVOnH during Mg2+ (de)intercalation are systematically explored through ex situ techniques. This work helps us to understand the mechanisms, and this can guide us in achieving a better design for high-performance positive electrodes for AMIBs.

Near-surface reconstruction in cobalt-free spinel positive electrodes for high-performance lithium-ion batteries.

Lattice strain critically affects electrochemical performance and durability of battery electrode materials. Here we report an electron-backscatter-diffraction-based imaging method to quantify lattice strain evolution and its spatial heterogeneity in two technologically important layered oxide cathodes (i.e. positive electrodes). Quantitative analysis is achieved by examining numerical distribution of the crystal misorientation data from thousands of positive electrode particles, which follows a positively skewed distribution. We reveal pronounced lattice strain heterogeneities both within individual grains and across different particles. These strain variations self-heal during relithiation but intensify with deeper delithiation and repeated cycling. The increased strain impedes Li-ion bulk diffusion, thereby limiting the maximum accessible capacity, especially at high current densities. Three-dimensional pole-figure analysis further identifies layer bending and layer twisting as the two major lattice distortion modes in the electrochemically cycled positive electrode particles. The accumulation of the unrecoverable layer bending governs the kinetically controlled capacity loss in the layered oxide positive electrodes.